Aircraft are commonly equipped with Cabin Pressure Control Systems (CPCSs), which maintain cabin air pressure within a desired range to increase passenger comfort during flight. A typical CPCS may include a controller, an actuator, and an outflow valve. The outflow valve is typically mounted on either a bulkhead of the aircraft or on the outer skin surface of the aircraft, and selectively fluidly couples the aircraft cabin and the atmosphere outside of the aircraft. During operation, the controller commands the actuator to move the outflow valve to various positions to control the rate at which pressurized air is transferred between the aircraft cabin and the outside atmosphere, to thereby control the pressure and/or rate of change of pressure within the aircraft cabin. The controller may be configured to command the actuator to modulate the outflow valve in accordance with a predetermined schedule or as a function of one or more operational criteria. For example, the CPCS may additionally include one or more cabin pressure sensors to sense cabin pressure and supply pressure signals representative thereof to the controller. By actively modulating the outflow valve, the controller may maintain aircraft cabin pressure and/or aircraft cabin pressure rate of change within a desired range.
In some aircraft, the outflow valve may be positioned on the aircraft outer skin surface such that when pressurized air is exhausted from the cabin, the exhausted air may provide additional forward thrust to the aircraft. Thus, outflow valves may sometimes be referred to as thrust recovery valves. Modern thrust recovery valves often contain two valve door elements to optimize the forward thrust that is created. Because of the pressure difference between the pressurized aircraft cabin and the outside atmosphere, and because of the potential energy of the pressurized air in the aircraft cabin, some thrust recovery valves have a rather distinctive shape. This shape accelerates the air as it passes between the thrust recovery valve door elements to provide a net aft thrust force.
Although thrust recovery valves, such as the one described above, are generally safe, reliable, and robust, these valves do exhibit certain drawbacks. For example, in order to maximize the produced thrust, the shapes of the valve door elements may be relatively complex. Moreover, because of the associated pressure load, the valve door elements are relatively robust in strength. Also, because of the very large aerodynamic loads during flight, the means of driving the valve door elements can be relatively complex, heavy, and expensive. In most instances, this results in the use of large swing arms being manufactured into the door elements to provide adequate mechanical advantage. Such swing arms do not inure to door elements being made of relatively lightweight materials, such as composite materials.
Hence, there is a need for a cabin pressure thrust recovery valve that is made of relatively lightweight materials, while at the same time having one or more valve door elements that may have relatively complex shapes, is relatively robust in strength, and/or does not have relatively large swing arms manufactured into the valve door elements. The present invention addresses at least this need.